Jim,
On Apr 24, 2009, at 11:53 AM, James McManus wrote:
Dane,
My tables do have SRID set in the geometry columns, but I have been
having problems using EPSG codes with mapnik. When I use src=
+init=epsg:2264 in my xml file I get a blank map, so I have been
using src=+proj=lcc +datum=NAD83 instead.
you mean 'srs' not 'src' right?
Also as long as you can do this in an interpreter without error you
should be fine using the Proj4 integer codes:
>>> from mapnik import *
>>> Projection('+init=epsg:2264')
Projection('+init=epsg:2264')
>>>
otherwise use the proj literal from:
http://spatialreference.org/ref/epsg/2264/mapnik/
If you are getting a blank map with the right projection then I'd
confirm that the 'srs' is properly set for you layers as well.
This works, but it looks like it may be the cause of the bad lexical
cast problem.
Okay, hard to say.
Looking at other emails on this list, I see that mapnik has a place
to set epsg codes ( allowedepsgcodes) in ogcserver.conf. Do I have
to use this method, when using epsg codes?
Yes, otherwise the OGCServer will throw an exception.
In my current configureation I'm using mapnik with openlayers
(Layer.WMS) and tilecache (type=MapnikLayer),
Okay, although with type=Mapnik TileCache is using Mapnik's python
bindings and I find it is easier to make TMS requests via OpenLayers.
with eather mod_python (must restart server, after each edit) or
just cgi when editing maps.
Okay.
Is there currently a conventional way to setup mapniks ogcserver to
work with tilecache?
Just set up the ogcserver as normal (I prefer WSGI) and use type=wms
in TileCache.
I currently I have epsg:2264 defined in both tilecache.cfg and in
Openlayers.
TileCache ignores the 'srs' parameter when using the type=Mapnik.
(i've been forgetting to submit a patch for this)
Therefore you need to supply:
projection=+proj=lcc +lat_1=36.16666666666666 +lat_2=34.33333333333334
+lat_0=33.75 +lon_0=-79 +x_0=609601.2192024384 +y_0=0 +ellps=GRS80
+datum=NAD83 +to_meter=0.3048006096012192 +no_defs
Possibly I could just incorporate ogcserver's wms.py into my
tilecache.py or tilecache.cgi scripts?
Why? Sounds tricky :)
Dane
Thanks
Jim
On Thu, Apr 23, 2009 at 6:59 PM, Dane Springmeyer
<[email protected]> wrote:
Hi James,
The lexical cast error is coming from a boost function that is used
to convert data types being pulled from postgis. Essentially what is
happening is likely due to problems involved in calculating extents
or the table srid, where data is not able to be correctly cast to a
new type required by the PosGIS plugin.
The I've seen this occur when querying an empty table and having
estimate_extent=True, because its impossible to convert null extents
to the required types. We should likely insert more friendly error
checking, but until then I would assume that lexical cast errors
indicate a problem in the data or parameters used to query postgis.
So, in your example below it looks like you are providing a manual
extent, so the above does not directly apply. But does your table
have an SRID set in the geometry columns? Is that extent value
correct/valid for your data projection? Does your user have
privileges to access all the tables including the geometry columns
table?
Dane
On Apr 23, 2009, at 11:25 AM, James McManus wrote:
I'm using mapnik with postgis and tilecache. Everything appears to
be working, except I am getting the error message "bad lexical cast:
source type value could not be interpreted as target" in my httpd/
error_log, even when I have debug set to off. I would like to
resolve this, so my error_log does not fill up. Below is part of
the error_output from the error_log:
[Thu Apr 23 13:57:06 2009] [error] [client 71.120.222.68]
datasource=0xbf8420 type=1
[Thu Apr 23 13:57:06 2009] [error] [client 71.120.222.68] size = 7
[Thu Apr 23 13:57:06 2009] [error] [client 71.120.222.68] dbname=wake
[Thu Apr 23 13:57:06 2009] [error] [client 71.120.222.68]
estimate_extent=false
[Thu Apr 23 13:57:06 2009] [error] [client 71.120.222.68]
extent=1947126.12, 596061.63, 2258533.48, 891583.72
[Thu Apr 23 13:57:06 2009] [error] [client 71.120.222.68]
host=localhost
[Thu Apr 23 13:57:06 2009] [error] [client 71.120.222.68]
table=wakepublicopenspace0902
[Thu Apr 23 13:57:06 2009] [error] [client 71.120.222.68] type=postgis
[Thu Apr 23 13:57:06 2009] [error] [client 71.120.222.68] user=apache
[Thu Apr 23 13:57:06 2009] [error] [client 71.120.222.68] bad
lexical cast: source type value could not be interpreted as target
[Thu Apr 23 13:57:06 2009] [error] [client 71.120.222.68] borrow
0xbbb8f0
[Thu Apr 23 13:57:06 2009] [error] [client 71.120.222.68] unknown
type_oid=408585
[Thu Apr 23 13:57:06 2009] [error] [client 71.120.222.68] return
0xbbb8f0
It appears to not like how I'm referenceing user?
Jim
_______________________________________________
Mapnik-users mailing list
[email protected]
https://lists.berlios.de/mailman/listinfo/mapnik-users
_______________________________________________
Mapnik-users mailing list
[email protected]
https://lists.berlios.de/mailman/listinfo/mapnik-users
